1. Field of the Invention
This invention relates to a system for recording and reproducing short segments of a received audiovisual signal.
2. Brief Description of the Prior Art
In accordance with the prior art, television programming has been recorded using systems employing unidirectional tapes. Such systems have generally demonstrated slow start up and slow rewind capabilities. It has also been difficult to locate a particular point of interest on a recorded videotape rapidly. It is therefore apparent that there is a need for a system capable of preserving a video program for future viewing along with a capability of identifying selected segments of the video program shortly after viewing for separate storage and/or replay. In prior art video cassette recording systems, rewind has been slow and slow motion has been provided with reduced quality. Prior art special effects video systems have also been relatively expensive and of questionable reliability.
Briefly, in accordance with the present invention, there is provided a system for storing and reproducing segments of a received audiovisual signal separate from any other recording of the signal for immediate or later replay on command of the viewer. The segments are sufficiently long to store a sequence of interest, such as a key portion of a sports event, and sufficiently short to be economically feasible and convenient to use. It is anticipated that this will be shorter than a standard VCR tape. A standard audiovisual signal, which can be analog or digital, is received from a station, a recording, a computer network or other standard source at a receiver and generally simultaneously or concurrently displayed and/or recorded at a recorder. The signal is displayed at the receiver and recorded in memory at the receiver. The memory can include one or more of a short segment magnetic memory, semiconductor memory, preferably in the form of a random access memory (RAM) or a plug-in memory which can be magnetic or semiconductor. The short segment memory is an endless memory, this being provided, for example, by an endless magnetic tape, a shift register in a ring configuration or by an addressable RAM wherein the memory elements are addressed sequentially in an endless manner by continually repeating the sequence. A conversion of analog signals to digital prior to recording allows storage in conventional solid state memory and simplifies the application of special effects to the recorded signal for subsequent reproduction and display. The recorder can also have provision to store the entire signal being received in a separate storage device and also provide the short segment storage separately as discussed above.
The received signal is viewed at a display by a viewer who can control the recording/playback of information to/from the endless memory, preferably by operating a remote control transmitter. When a viewed segment is to be retained, the viewer operates the transmitter to provide a signal to a controller. The controller immediately or after some predetermined time delay freezes the then recorded information in the short segment storage. That is, recording over the recently recorded information is stopped. The transmitter can then be operated to cause replay of the information recorded in the short segment storage at the receiver or retention of this information in storage for future use. It is apparent that the recorded information can be operated upon using known techniques to provide special effects, such as single frame viewing, slow motion, zoom and the like. The special effects can also be added to the signal prior to recordation.
A standard video recorder can be used in conjunction with the present invention. An audiovisual signal can be received directly from the standard video recorder or from a receiver. A switch under control of the controller applies the received signal to one or more of a plug-in-module, a short segment recorder which can be a semiconductor memory such as a RAM, an endless video tape or other recording device and a standard video recording system such as, for example, a semiconductor storage device or a VCR tape. When a signal of appropriate type is received at the switch, indicating that a short segment is to be retained, the switch ceases to send signals to the module or short segment VCR either immediately or after a predetermined time delay and freezes the information stored in these short segment storage devices. Upon appropriate signalling from the controller, the information stored in the plug-in module and/or the short segment VCR is played back through the switch to the receiver. The information played back can be provided with special effects either before recordation thereof or during the playback. The special effects can be provided by the switch or by other standard devices.
The short segment continuous recorder can be a stand alone appliance to be used with a television set, or it can be incorporated into a television set, a video cassette recorder, video player or computer. If incorporated into a VCR, the short segment can serve the function of providing special effects, such as freeze frame or rewind/display of the previously viewed segment, optionally in slow motion or with other effects, such as zoom.